Extended pharmacological miosis is superfluous after glaucoma angle surgery: A retrospective study

Background: Pilocarpine is commonly used after angle surgery for glaucoma despite a host of side effects and risks. We hypothesized that a pharmacological miosis during the first two months does not improve short- and long-term results of trabectome-mediated ab interno trabeculectomy. Methods: In this retrospective comparative 1-year case series, we compared 187 trabectome surgery eyes with (P+) or without (P-) 1% pilocarpine for two months. Primary outcome measures were the surgical success defined as intraocular pressure (IOP) ≤ 21 mmHg and decreased ≥ 20%, and no secondary glaucoma surgery. Secondary outcome measures were the number of glaucoma medications, complications, and IOP. Results: We categorized 86 (46%) eyes as P- and 101 (54%) eyes as P+. The mean age was 69.8±10.1 in P- and 70.5±9.4 in P+ (P=0.617) with equal gender distribution (P=0.38). The cumulative probability of qualified success at 12 months was 78.1% in the P- and 81% in the P+ (P=0.35). The IOP was decreased significantly from 20.2±6.8 mmHg at baseline to 15.0±4.8 mmHg at 12 months follow-up in P- (P=0.001) and 18.8±5.3 and 14.7±4.0, respectively (P=0.001). The medications decreased significantly from 1.4±1.2 in P- and 1.4±1.2 in P+ at baseline to 1.0±1.2 and 0.7±1.0, respectively (P=0.183). P- and P+ did not differ in IOP or medications (all P>0.05). In Multivariate Cox Regression models, the baseline IOP and central corneal thickness were associated with failure. Conclusions: Use of postoperative pilocarpine does not improve the efficacy of trabectome surgery.